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Return parameter null in controller from ajax

I don't know what happened the value sent to the controller is always null, even though in the console.log the value is there, please I need help
this is my ajax:
$('#ddlItemName').change(function () {
var ItemCode = $('#ddlItemName').text();
if (ItemCode != '') {
var RequestParam = {
search: ItemCode
}
console.log(RequestParam);
$.ajax({
url: '/Order/CustomerItemOrders',
type: 'POST',
data: JSON.stringify(RequestParam),
contentType: 'application/json; charset=utf-8',
success: function (data) {
alert(data[0].Name);
},
error: function (data) {
toastr.error(data);
}
});
}
$('#ddlItemName').text('');
});
This is my controller :
[HttpPost]
public JsonResult CustomerItemOrders([FromBody] string search)
{
var result = _order.BindCustomerOrders(search);
return Json(result.data);
}
This is my error :
enter image description here
I've tried adding '[FromBody]' but the value parameter still doesn't get sent

I recomend you add the parameter to query
If you insist on pass the value with request body
Try creat a model:
public class SomeModel
{
public string search{get;set;}
}
in your controller:
public JsonResult CustomerItemOrders([FromBody] SomeModel somemodel)
{
.......
}

Ajax POST an object with javascript, but the value in backend is null, why?

So on button click there is a function sendEmail(). Alert is working fine, I can see my datas there. But on backend I can't see anything, just everything is null.
function sendEmail() {
var datas = new Object();
datas.mail = $('#contactDropdownList').val();
datas.mailobject = $('#emailObject').val();
datas.text = $('#emailText').val();enter code here
alert(datas.mail + datas.mailobject + datas.text);
$.ajax({
type: "POST",
dataType: "json",
url: "/Email/sendEmail",
contentType: 'application/json; charset=UTF-8',
data: JSON.stringify({ items: datas }),
success: function (data) {
console.log(data);
//do something with data
},
error: function (jqXHR, textStatus, error) {
//log or alert the error
console.log(error);
}
});
}
C# code:
public class MyClass
{
public string Email { get; set; }
public string Object { get; set; }
public string Text { get; set; }
}
[HttpPost]
public IActionResult sendEmail(MyClass items)
{
return Json(new { data="Ok" });
}
items.Email, items.Object and items.Text are null.
And the return valu is null as well, because in javascript success: function (data) { console.log(data);
is empty string.
What can be the problem? Thank you!

Model binder expects json content to match C# class. Your datas object should look like that
var datas = {
email: $('#contactDropdownList').val(),
object: $('#emailObject').val(),
text: $('#emailText').val()
}
Since you wrapped your object ({ items: datas }), you may think it will be mapped to sendEmail(MyClass items), but in reality items name does not matter, you can change variable name to any other name you like
Make sure you apply [FromBody] attribute to your parameter like that
[HttpPost]
public IActionResult sendEmail([FromBody]MyClass items)
Complete demo:
<script>
function sendSmth() {
var data = {
Email: 'email',
Object: 'object',
Text: 'text'
};
$.ajax({
type: "POST",
dataType: "json",
url: "/home/index",
contentType: "application/json",
data: JSON.stringify(data),
success: function (datas) {
console.log(datas)
}
})
}
</script>
And controller
[HttpPost]
public IActionResult Index([FromBody]MyClass obj)
{
return View();
}

As someone has noted, you have a mismatch between what you're sending to the controller and what the model the modelbinder is expecting. You can also vastly simply your AJAX code:
function sendEmail() {
var data = {
Email: $('#contactDropdownList').val(),
Object: $('#emailObject').val(),
Text: $('#emailText').val()
};
$.post("/Email/sendEmail", data)
.done(function (response) {
console.log(response);
//do something with response
})
.fail(function (jqXHR, textStatus, error) {
//log or alert the error
console.log(error);
});
}
You don't really need to specify the content type or data type - the $.post helper's defaults work just fine for what you've shown.

Delete record by using ajax from database EntityFramework

I am beginner and trying to delete the record from database by using JavaScript, Ajax and Json in MVC Entity Framework. But my delete button is not working well.
In controller class my action code is
public ActionResult Delete(int id) {
using (StudentContext db = new StudentContext()) {
Student std = db.Student.Where(x => x.Id == id).FirstOrDefault<Student>();
db.Student.Remove(std);
db.SaveChanges();
}
return Json(true, JsonRequestBehavior.AllowGet);
}
and my JavaScript code is
<button id='deleteRecord'>delete</button>
$("#deleteRecord").click(function () {
var StudentId = $(this).val();
var stdId = parseInt(StudentId);
$.ajax({
url: "/AjaxStudent/Delete",
type: 'Delete',
data: {
StudentId: stdId
}
}).done(function () {
alert("Deleted")
});
});
}).error(function () {
alert("Failed")
});
I shall be very thankful if anybody help me.

You need to add your model id in jquery data tag:
<button id='deleteRecord' data-model-id="#model.Id">delete</button>
Then in javascript code:
$("#deleteRecord").click(function () {
var StudentId = $(this).data("model-id");
var url = "/AjaxStudent/Delete/" + StudentId;
$.ajax({
url: url,
type: 'Delete',
}).done(function () {
alert("Deleted")
});
});
}).error(function () {
alert("Failed")
});

I think that the error comes from the type attribute of your ajax call. You assign "delete" to this attribute, but it must be "POST":
$.ajax({
url: "#Url.Action("Delete","AjaxStudent")",
type: "POST", // here is your problem,
data: { StudentId: stdId },
dataType: 'json',
success: function() {
alert("Deleted");
},
error: function(dat) {
alert(data.x);
}
});
And the action method in your controller must be decorated with [httppost] :
[HttpPost]
public JsonResult Delete(int StudentId)
{
using (StudentContext db = new StudentContext())
{
Student std = db.Student.Where(x => x.Id == StudentId).FirstOrDefault<Student>();
db.Student.Remove(std);
db.SaveChanges();
}
return Json(true, JsonRequestBehavior.AllowGet);
}

you should try by changing :
$.ajax({
url: "/AjaxStudent/Delete",
type: 'Delete',
data: {
StudentId: stdId
}
to:
$.ajax({
url: "/AjaxStudent/Delete",
type: 'Delete',
data: {
'id':stdId
}

After lots of time I am able to resolve my problem.
Now my javaScript code
<button class='deleteRecord' data-stid=" + students[i].Id + " >delete</button>
$(".deleteRecord").click(function () {
var StudentId1 = $(this).data("stid");
debugger;
$.ajax({
url: "/AjaxStudent/Delete/" + StudentId1,
type: "Post"
}).done(function () {
getAllStudents();
});
});
});
Controller.cs
public ActionResult Delete(int id) {
using (StudentContext db = new StudentContext()) {
Student std = db.Student.Where(x => x.Id == id).FirstOrDefault();
db.Student.Remove(std);
db.SaveChanges();
}
return Json(true, JsonRequestBehavior.AllowGet);
}

Getting failed on returning string from API to JSON AJAX POST in mvc Javascript

$("#modelchange").change(function() {
$.ajax({
type: 'POST',
url: '#Url.Action("GetStore")',
dataType: 'json',
data: {
Id: $("#modelchange").val()
},
success: function(storeName) {
$('#storeName').text("Store : " + storeName);
},
error: function(ex) {
alert('Failed to load store Value');
}
});
return false;
});
API
[HttpPost]
public string GetStore(int Id)
{
string storeName = db.AddInktoStores.Single(a => a.InkId == Id)).Store.StoreName;
return storeName;
}
Above mentioned is a controller and JSON in my javascript.
I am trying to get Store Name but I keep getting throw into my error: function
Please Help!

Try to return data as:
[HttpPost]
public JsonResult GetStore(int Id)
{
string storeName = db.AddInktoStores.Single(a => a.InkId == Id)).Store.StoreName;
return Json(storeName);
}

Calling controller with ajax in mvc

I'm trying to fetch data from a controller and update my view using ajax.
This is my controller:
public class PatientController
{
DatabaseContext db = new DatabaseContext();
public JsonResult GetPatientFromCpr()
{
var patient = db.Patients.FirstOrDefault(p => p.Cpr == "2410911615");
return new JsonResult() { Data = patient, JsonRequestBehavior = JsonRequestBehavior.AllowGet };
}
}
And this is my ajax call:
function getPatient() {
cpr2 = $("#cpr-first").val() + $("#cpr-last").val();
$.ajax(
{
url: '/Patient/GetPatientFromCpr',
dataType: 'json',
success: function () {
alert("success");
},
error: function () {
alert("error");
},
});
}
When i call the function i always get the error alert.
GET http://localhost:51140/Patient/GetPatientFromCpr 404 (Not Found)
Can someone point out what's wrong?
(EDIT)
I now get a new error after adding ": Controller"
GET http://localhost:51140/Patient/GetPatientFromCpr 500 (Internal Server Error)

Your 'PatientController' is not a Controller (it does not inherit from Controller)
public class PatientController : Controller
{
....
}

Inherit you PatientController with Base Controller Class
public class PatientController : Controller
In controller
public JsonResult GetPatientFromCpr()
{
var patient = db.Patients.where(p => p.Cpr == "2410911615").FirstOrDefault();
return new JsonResult() { Data = patient, JsonRequestBehavior = JsonRequestBehavior.AllowGet };
}
And Specify the type of ajax calling
type: "POST" or type: "GET" ....
This will help you to fix error

Try using this, may be this works..!!
View:
function getPatient() {
cpr2 = $("#cpr-first").val() + $("#cpr-last").val();
$.ajax(
{
url: '/Patient/GetPatientFromCpr',
//dataType: 'json',
type:"POST", // GET or POST
success: function () {
alert("success");
},
error: function () {
alert("error");
},
});
}
Controller:
public class PatientController : Controller
{
....
}